Power-line communication (“PLC”) is a technology that allows power and data to be carried simultaneously on the same conductive path or paths. One convenient application of this technology for consumers is in the area of PLC adapters. A PLC adapter is a device that can be plugged in to a standard electrical outlet and transmit or receive data (via an internal modem of the adapter) over the phase line (also referred to as the “line” or “hot”) and use the current from the outlet to power the adapter.
A PLC device typically includes a power supply, such as an alternating-current, direct-current (“AC/DC”) power supply. An inevitable side effect of the power supply is that it generates signal disturbances in the differential and common mode. While such disturbances can usually be kept below regulatory limits through the use of standard electromagnetic interference (“EMI”) reduction hardware, they are often still high enough to be in the sensitivity range of the modem of the PLC device, thereby affecting the modem's dynamic range.